Valve-operating mechanism.



R. A. cANNoN.

VALVE OPERATING MECHANISM.

APPLICATION FILED JULY29| I915- Patented 11111620, 1916.

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' THE COLUMBIA PLANOGRAPH C0., WASHINGTON, D. C

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ROY A. CANNON, 0F VANCOUVER, BRITISH COLUMBIA, CANADA.

VALVE-OPERATING MECHANISM.

Application filed July 29, 1915. Serial No. 42,515.

To all whom it may concern:

Be it known that I, ROY A. CANNON, a citizen of the United States, residing at Vancouver, in the Province of British Columbia, Canada, have invented certain new and useful Improvements in Valve-Operating Mechanisms, of which the following is a specification.

This invention relates to an engine throttle valve, such as is used for controlling the admission of steam to the cylinders of hoisting or excavating engines and is a modification of that form of valve wherein control of the steam is effected by a flat face slide movable across a port face in which is the port admitting; steam from the boiler to the engine cylinder. Such valves, as usually made, control only the admission of steam to the cylinders and lowering the hoist has to be effected by means of a clutch brake which is not only an added cost to the first cost and maintenance of the engine but is ineffective and unreliable.

In the valve, which is the subject of this application, the port face and valve of the throttle are provided with supplementary ports whereby the engine steam pipe connection may be opened to the atmosphere to relieve the engine cylinders of the compressed air against which they must act while running backward and this relief exit is under such complete control by the valve that the compressed air may be retained as desired to check acceleration of the descent of the hoist. The valve by which these re sults are attained is fully described in the following specification, reference being made to the drawings by which it is accompanied, in which:

Figure 1 is a vertical section through the ports of the valve, and Fig. 2, a horizontal section of a steam chest showing the port face of the valve in plan, the tooth segment and the valve being omitted.

In these drawings 2 represents the steam pipe connection from the boiler to the throttle valve, 3 the connection of the same pipe from the valve to the engine, and 4: a pipe delivering from the valve to the atmosphere.

The steam pipe 2 from the boiler is connected to a cover plate 5 which is jointed on the flanged upper side of the valve steam chest 6, the lower side of which is jointed to a port face 7 having ports 8 and 9. The

port 8 communicates with the steam pipe connection 3 from the valve to the engine, and the port 9 connects with the delivery pipe 4: to the atmosphere. These ports 8 and 9 are adjacent and parallel to one another and are in plan preferably elongated rectangles. The valve 10 which moves across them has an exhaust port 11 in it, the width of which is sufficient to connect the two ports, and along that side which is adjacent to the steam port 8 the face of the valve is of sufficient width to cover that port when centrally over it. The valve is shown in the drawing as movable across the ports by a small toothed segment 12, the teeth of which mesh with corresponding teeth formed in the back of the valve, the segment having an open ended slot 13, in which fits the flattened sides of a rotatable valve spindle 14: which passes through a packing gland 15 in one side of the steam chest and has a supporting bearing 16 in the other side. The spindle is provided with a handle lever outside the valve casing. With an engine throttle valve so constructed, the valve may be moved to the left and will uncover the port 8 to admit steam from the boiler steam pipe 2 to the engine steam pipe 3 for hoisting, and when it is required to lower the hoist the valve 10 is moved to cover the port 8 and the steam is cut off and as the engine runs backward its pistons will pump air into the steam chest sufficient to check the too rapid descent of the hoist, and the amount of air pressure retained is under complete control as the valve 10 may be moved to the right to permit escape of any desired amount of the accumulated air pressure, so that the engineer can lower his hoist at any desired speed.

I am aware that supplementary relief valves have heretofore been used to provide for the escape of air from a steam pipe to re lieve the cylinder pistons of the air pumped by them when the engine is running backward, but in no case with which I am acquainted has such release been effected by the engine throttle valve, so that the lioisting and lowering of the engine are under control by one valve.

Having now particularly described my invention, I hereby declare that what I claim as new and desire to be protected in by Letters Patent, is:

In an operating mechanism, a sliding tion to fit in said bifurcated portion, said member the back of said member having segment and said rock shaft being adapted rack teeth, a segment of gear teeth located to be readily connected and disconnected 11 above said sliding member and meshing from one another, substantially as shown. with the teeth on the back of the sliding In testimony whereofI aflix my signature. member, said segment having a bifurcated portion, a rock shaft having a notched por- ROY A. CANNON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 01 Puma,

' Wuhington, D. 0. 

